gnrc_netif: make _get_iid() just wrapper around _iid_from_addr()

This way the IID generation gets much simplified and code duplication
is avoided since it removes GNRC's requirement for NETOPT_IPV6_IID.

nanocoap: fix server-side option_count overflow

kw2xrf: Don't use netdev_ieee802154_t for link layer address

make: handle disabled default modules before dependencies

mrf24j40: Don't use netdev_ieee802154_t for link layer address

cpu/lpc2387: remove newlib dependencies

This change modifies the mrf24j40 driver to read the address directly
from the device instead of returning the netdev_ieee802154_t member

This change modifies the kw2xrf_get_addr_short function to retrieve the
short address from the device and not from netdev

This change ensures that the endianess returned by the get_addr_long
is consistent with the endianess of the get_addr_short

drivers/adcxx1c: improve error handling

 tests: introduce dedicated `gnrc_rpl_srh` test

tests/gnrc_ipv6_ext: port to scapy

frdm-k64f: Add LPTMR configuration

cpu/esp: esp_now_netdev fixes and optimizations

drivers/pulse_counter: refactor the prototypes of read funcs

cpu/esp8266: doc extended

Documentation is generated by doxygen from doc.txt

sock_dns: fix out-of-bound errors

Fixes #10739

drivers/cc2420: Implemented missing drop case